Characterization of the UDP-N-acetylgalactosamine binding domain of bovine polypeptide N-acetylgalactosaminyltransferase T1
| Autor: | Véronique Piller, Stéphanie Duclos, Pedro Da Silva, Friedrich Piller, Françoise Vovelle |
|---|---|
| Přispěvatelé: | Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC) |
| Rok vydání: | 2004 |
| Předmět: |
UDP-GalNAc
Threonine Stereochemistry Molecular Sequence Data Gene Expression Bioengineering 01 natural sciences Biochemistry comparative molecular modelling Substrate Specificity Structure-Activity Relationship 03 medical and health sciences chemistry.chemical_compound Protein structure glycosyltransferases Ribose Serine Animals Point Mutation Amino Acid Sequence Binding site N-acetylgalactosamine binding polypeptide {alpha}N-acetylgalactosaminyltransferases Molecular Biology Peptide sequence 030304 developmental biology chemistry.chemical_classification 0303 health sciences Binding Sites 010405 organic chemistry Hydrogen bond Uracil Protein Structure Tertiary 0104 chemical sciences Amino acid carbohydrates (lipids) Amino Acid Substitution Models Chemical chemistry Uridine Diphosphate N-Acetylgalactosamine Mutagenesis Site-Directed N-Acetylgalactosaminyltransferases Cattle lipids (amino acids peptides and proteins) mutagenesis Protein Binding Biotechnology |
| Zdroj: | Protein Engineering, Design and Selection Protein Engineering, Design and Selection, Oxford University Press (OUP), 2004, 17 (8), pp.635-646. ⟨10.1093/protein/gzh075⟩ |
| ISSN: | 1741-0134 1741-0126 |
| DOI: | 10.1093/protein/gzh075 |
| Popis: | UDP-GalNAc:polypeptide {alpha}N-acetylgalactosaminyltransferases (ppGaNTases) transfer GalNAc from UDP-GalNAc to Ser or Thr. Structural features underlying their enzymatic activity and their specificity are still unidentified. In order to get some insight into the donor substrate recognition, we used a molecular modelling approach on a portion of the catalytic site of the bovine ppGaNTase-T1. Fold recognition methods identified as appropriate templates the bovine {alpha}1,3galactosyltransferase and the human {alpha}1,3N-acetylgalactosaminyltransferase. A model of the ppGaNTase-T1 nucleotide-sugar binding site was built into which the UDP-GalNAc and the Mn2+ cation were docked. UDP-GalNAc fits best in a conformation where the GalNAc is folded back under the phosphates and is maintained in that special conformation through hydrogen bonds with R193. The ribose is found in van der Waals contacts with F124 and L189. The uracil is involved in a stacking interaction with W129 and forms a hydrogen bond with N126. The Mn2+ is found in coordination both with the phosphates of UDP and the DXH motif of the enzyme. Amino acids in contact with UDP-GalNAc in the model have been mutated and the corresponding soluble forms of the enzyme expressed in yeast. Their kinetic constants confirm the importance of these amino acids in donor substrate interactions. |
| Databáze: | OpenAIRE |
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